1 /* $OpenBSD: readpassphrase.c,v 1.12 2001/12/15 05:41:00 millert Exp $ */ 2 3 /* 4 * Copyright (c) 2000 Todd C. Miller <Todd.Miller@courtesan.com> 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. The name of the author may not be used to endorse or promote products 16 * derived from this software without specific prior written permission. 17 * 18 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, 19 * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY 20 * AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL 21 * THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, 22 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, 23 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; 24 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, 25 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR 26 * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF 27 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 28 * 29 * $OpenBSD: readpassphrase.c,v 1.12 2001/12/15 05:41:00 millert Exp $ 30 * $FreeBSD: src/lib/libc/gen/readpassphrase.c,v 1.6.2.2 2002/06/30 13:54:26 des Exp $ 31 * $DragonFly: src/lib/libc/gen/readpassphrase.c,v 1.2 2003/06/17 04:26:42 dillon Exp $ 32 */ 33 34 #include <ctype.h> 35 #include <errno.h> 36 #include <fcntl.h> 37 #include <paths.h> 38 #include <pwd.h> 39 #include <signal.h> 40 #include <string.h> 41 #include <termios.h> 42 #include <unistd.h> 43 #include <readpassphrase.h> 44 45 static volatile sig_atomic_t signo; 46 47 static void handler(int); 48 49 char * 50 readpassphrase(const char *prompt, char *buf, size_t bufsiz, int flags) 51 { 52 ssize_t nr; 53 int input, output, save_errno; 54 char ch, *p, *end; 55 struct termios term, oterm; 56 struct sigaction sa, saveint, savehup, savequit, saveterm; 57 struct sigaction savetstp, savettin, savettou; 58 59 /* I suppose we could alloc on demand in this case (XXX). */ 60 if (bufsiz == 0) { 61 errno = EINVAL; 62 return(NULL); 63 } 64 65 restart: 66 /* 67 * Read and write to /dev/tty if available. If not, read from 68 * stdin and write to stderr unless a tty is required. 69 */ 70 if ((input = output = _open(_PATH_TTY, O_RDWR)) == -1) { 71 if (flags & RPP_REQUIRE_TTY) { 72 errno = ENOTTY; 73 return(NULL); 74 } 75 input = STDIN_FILENO; 76 output = STDERR_FILENO; 77 } 78 79 /* 80 * Catch signals that would otherwise cause the user to end 81 * up with echo turned off in the shell. Don't worry about 82 * things like SIGALRM and SIGPIPE for now. 83 */ 84 sigemptyset(&sa.sa_mask); 85 sa.sa_flags = 0; /* don't restart system calls */ 86 sa.sa_handler = handler; 87 (void)_sigaction(SIGINT, &sa, &saveint); 88 (void)_sigaction(SIGHUP, &sa, &savehup); 89 (void)_sigaction(SIGQUIT, &sa, &savequit); 90 (void)_sigaction(SIGTERM, &sa, &saveterm); 91 (void)_sigaction(SIGTSTP, &sa, &savetstp); 92 (void)_sigaction(SIGTTIN, &sa, &savettin); 93 (void)_sigaction(SIGTTOU, &sa, &savettou); 94 95 /* Turn off echo if possible. */ 96 if (tcgetattr(input, &oterm) == 0) { 97 memcpy(&term, &oterm, sizeof(term)); 98 if (!(flags & RPP_ECHO_ON)) 99 term.c_lflag &= ~(ECHO | ECHONL); 100 if (term.c_cc[VSTATUS] != _POSIX_VDISABLE) 101 term.c_cc[VSTATUS] = _POSIX_VDISABLE; 102 (void)tcsetattr(input, TCSAFLUSH|TCSASOFT, &term); 103 } else { 104 memset(&term, 0, sizeof(term)); 105 memset(&oterm, 0, sizeof(oterm)); 106 } 107 108 (void)_write(output, prompt, strlen(prompt)); 109 end = buf + bufsiz - 1; 110 for (p = buf; (nr = _read(input, &ch, 1)) == 1 && ch != '\n' && ch != '\r';) { 111 if (p < end) { 112 if ((flags & RPP_SEVENBIT)) 113 ch &= 0x7f; 114 if (isalpha(ch)) { 115 if ((flags & RPP_FORCELOWER)) 116 ch = tolower(ch); 117 if ((flags & RPP_FORCEUPPER)) 118 ch = toupper(ch); 119 } 120 *p++ = ch; 121 } 122 } 123 *p = '\0'; 124 save_errno = errno; 125 if (!(term.c_lflag & ECHO)) 126 (void)_write(output, "\n", 1); 127 128 /* Restore old terminal settings and signals. */ 129 if (memcmp(&term, &oterm, sizeof(term)) != 0) 130 (void)tcsetattr(input, TCSANOW|TCSASOFT, &oterm); 131 (void)_sigaction(SIGINT, &saveint, NULL); 132 (void)_sigaction(SIGHUP, &savehup, NULL); 133 (void)_sigaction(SIGQUIT, &savequit, NULL); 134 (void)_sigaction(SIGTERM, &saveterm, NULL); 135 (void)_sigaction(SIGTSTP, &savetstp, NULL); 136 (void)_sigaction(SIGTTIN, &savettin, NULL); 137 (void)_sigaction(SIGTTOU, &savettou, NULL); 138 if (input != STDIN_FILENO) 139 (void)_close(input); 140 141 /* 142 * If we were interrupted by a signal, resend it to ourselves 143 * now that we have restored the signal handlers. 144 */ 145 if (signo) { 146 kill(getpid(), signo); 147 switch (signo) { 148 case SIGTSTP: 149 case SIGTTIN: 150 case SIGTTOU: 151 signo = 0; 152 goto restart; 153 } 154 } 155 156 errno = save_errno; 157 return(nr == -1 ? NULL : buf); 158 } 159 160 char * 161 getpass(const char *prompt) 162 { 163 static char buf[_PASSWORD_LEN + 1]; 164 165 if (readpassphrase(prompt, buf, sizeof(buf), RPP_ECHO_OFF) == NULL) 166 buf[0] = '\0'; 167 return(buf); 168 } 169 170 static void handler(int s) 171 { 172 173 signo = s; 174 } 175